1. Field of the Invention
The invention relates to a process for the extraction of valuable oxygen-bound metals by reduction in metallurgical vessels. The invention further relates to a melting furnace unit with a separating wall which separates the vessel into two parts and extends from the furnace roof into the vessel. The furnace unit further has a device for supplying heat energy as well as devices for feeding material and melt removal, and a connection to a gas purification unit.
2. Description of the Prior Art
In metallurgical processes for extracting valuable oxygen-bound metals, such as lead or copper, by reduction, the reducing agent needed for the reduction process is usually provided by charging onto the molten bath. Because of the great difference in specific weight between the reducing agent, usually coke, and the metallurgical melt, which is to be equated with a slag melt, the reducing agent in the form of coke is only able to float as a top layer on the melt. This results in only slight effective contact of the reductant with the large volume of metallurgical oxidic bath to be reduced. The consequences of this poor contact are very long holding and reduction times (as long as days) with a considerable expenditure of holding energy.
In addition, a process is known from DE OS 25 09 061 in which material containing metal oxide is reduced in a glowing coke bed, which is shaped like a horizontal ring and heated electrically. In this process, which essentially serves to extract a metal melt containing carbon from material containing metal oxide, the melted metal is prevented from forming a coherent molten layer below the coke bed.
Along with the difficulty in controlling the prevention of the formation of a coherent molten layer below the coke bed, other disadvantages of this process include the use of an annular furnace with its large number of individual moving parts which are subject to wear.
A unit is known from DE 36 14 048 A1 which has a reactor filled with molten metal, in which a separating wall, which has at least one opening for the molten metal on the floor of the reactor, is located in the central area of the reactor. This unit is used for the gasification of inferior fuels in a molten metal melting bath, particularly an iron melting bath, and is not suitable for reducing an oxidic metallurgical melt of value. Inferior fuels, including used oil, household refuse, bulky refuse, waste materials, automobile tires, etc., are introduced here into the metal melt. The carbon contained in the inferior fuel, as well as the sulphur, pass into solution in the iron bath. The non-gasifiable and non-soluble components of the inferior fuels are slagged and immediately removed from the reactor chamber via the discharge organ. No intimate contact occurs here between a reducing agent and the slag melt.